While there have been numerous early inventions of the electric guitar, George D. Beauchamp 1939 patent (U.S. Pat. No. 2,152,783 filed May 26, 1936) can be seen as the first design incorporating a magnetic induction transducer as a means to suppress the problem of acoustic feedback from the amplifier and loudspeaker. Feedback occurs when the guitar transducer senses the amplified signal through the loudspeaker as being as loud as, or louder than, the vibrating string of the guitar. It is still possible to apply enough gain or to place the guitar close to the loudspeaker and create an unstable feedback howling sound, but the magnetic induction pickup has proven to be the most effective at keeping feedback under control. Unfortunately, the electronic signal of a magnetic induction pickup lacks the high frequency structure to reproduce the acoustic guitar sound one hears without amplification. Vibration sensors can be used which offer a closer sound image than the magnetic induction pickup, but the vibration signal is not the same as the acoustic signal and the vibration signal is still sensitive to uncontrolled acoustic feedback.